Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Quantas escolhas existem para defensor de costas para rodadas maiores que 11?
 ###Tabelas: CREATE TABLE ground_history (ground_history_id AUTO_INCREMENT PRIMARY KEY, Name of ground VARCHAR, Location VARCHAR, Year VARCHAR, FC matches VARCHAR, LA matches VARCHAR, T20 matches VARCHAR, Total VARCHAR) CREATE TABLE nfl_draft (nfl_draft_id AUTO_INCREMENT PRIMARY KEY, Round INT, Pick INT, Player VARCHAR, Position VARCHAR, School/Club Team VARCHAR) CREATE TABLE whanau_house_system (whanau_house_system_id AUTO_INCREMENT PRIMARY KEY, House name VARCHAR, House mascot VARCHAR, House colour VARCHAR, Year opened INT, House leader VARCHAR) CREATE TABLE series_ratings (series_ratings_id AUTO_INCREMENT PRIMARY KEY, Season INT, # of Episodes INT, Timeslot VARCHAR, Season Premiere VARCHAR, Season Final VARCHAR, Peak Audience INT, Average Audience INT, Average Nightly Rank VARCHAR, Average Weekly Rank VARCHAR, Average Yearly Ranking VARCHAR) CREATE TABLE doubles_champion_5 (doubles_champion_5_id AUTO_INCREMENT PRIMARY KEY, Outcome VARCHAR, Date VARCHAR, Tournament VARCHAR, Surface VARCHAR, Partner VARCHAR, Opponents in the final VARCHAR, Score in the final VARCHAR)  
SELECT COUNT Pick FROM nfl_draft WHERE Position = defensive back AND Round > 11